Search PubMed⌕ Search

Biomedical subjects

R Yoshimura

Publications and source records attributed to R Yoshimura.

At least 163 records · Page 9Linked to original sources
PubMed1981

Stimulation of protein and RNA synthesis by methylmercury chloride in the liver of intact and adrenalectomized rats.

(1) A single injection of methylmercury chloride in the rat (10-50 mg/kg) increased both in vivo and in vitro rates of 14C-leucine incorporation into the protein of the post-mitochondrial supernatant fraction of the liver. In contrast, no stimulation of protein synthesis was observed in the brain of the methylmercury-treated rats. (2) Methylmercury administration also stimulated RNA polymerase activities in isolated hepatic nuclei, stimulation of Mg-dependent activity being higher than that of Mn-dependent activity. (3) In experiments with adrenalectomized rats, it was found that the stimulatory effect of methylmercury on protein and RNA synthesis in the liver was mediated partly through the adrenal gland. (4) Analysis of serum by starch-block electrophoresis revealed that synthesis of all serum proteins, including albumin and alpha-gamma globulin fractions, was stimulated by methylmercury treatment. (5) These results suggest that the observed effects of methylmercury on the liver depend on mechanisms other than enhancement of the synthesis of acute-phase proteins.

Adrenalectomy↗
PubMed1979

Studies on hemorrhagic tendency in cirrhosis of the liver.

Recently it has been paid attention whether the liver diseases might induce the disseminated intravascular coagulation (DIC) or not, although it has well known that liver cirrhosis contribute to the hemorrhagic diathesis. In this paper, we studied on the hemorrhagic tendency and hemostatic tests in the patients with liver cirrhosis in order to clarify the coagulation and fibrinolytic activity. We can conclude that the hemorrhagic diathesis occurs due to the complex of decreases in platelet number, platelet functions, clotting factors, and increased fibrinolytic activity. The increased fibrinolytic activity may be primary and the frequency of clinically important DIC is quite low.

Adult↗
PubMedDate not supplied

Sonographic appearances of malignant lymphoma of the salivary glands.

PURPOSE: We undertook this retrospective study to describe the sonographic findings in patients with malignant lymphoma of the major salivary glands. METHODS: We reviewed the sonograms and medical records of 7 patients with histologically proven lymphoma of the parotid (3 patients) or submandibular glands (4 patients). RESULTS: Primary lymphoma was found in 1 parotid gland and 2 submandibular glands. The remaining 4 cases were secondary lymphomas. One patient had been diagnosed with Sjögren's syndrome and had been followed up with sonography. In parotid glands, both parenchymal and intraparotid nodal lymphomas were found. All submandibular gland tumors were parenchymal. Intraparotid nodal involvement appeared as multiple small nodules with relatively smooth margins, whereas the parenchymal parotid and submandibular gland lymphomas were larger (25 to 45 mm in longitudinal diameter) and showed various degrees of margin irregularity. All tumors were hypoechoic relative to the normal parenchyma. The primary parotid lymphoma and intraparotid nodal lymphomas had a homogeneous echotexture; the secondary parotid lymphomas and submandibular gland lymphomas were heterogeneous. One submandibular gland lymphoma showed intratumoral echogenic stripes. Neither calcification nor cystic degeneration was observed within the lesions. CONCLUSIONS: Lymphomas of the salivary glands present a variety of sonographic appearances, ranging from multiple small, hypoechoic nodules to an irregularly shaped heterogeneous mass without cystic areas or calcifications.

Adult↗
PubMedDate not supplied

Human interleukin-10 transduced fetal liver stem cells prolong survival of mouse skin and heart allografts.

Interleukin (IL)-10 regulates immune responses, acting as a suppressive cytokine by inhibiting the synthesis of Th1 cytokines, such as IL-2 and interferon (IFN)-gamma. It also strongly down-regulates major histocompatibility complex (MHC) class II determinants on antigen presenting cells (APC). On the other hand, long-term tolerance is well correlated with the persistence of a peripheral microchimerism. In this study, we investigated the synergistic effect of human IL-10 (huIL-10) and hematopoietic microchimerism for the induction of long-term tolerance. Irradiated Balb/c mice (H-2d) were used as recipients (fetal liver stem cells [FLSC], skin and heart) and C57BL/6 (H-2b) mice were used as donors of FLSC, skin and heart. Recipients were simultaneously transplanted with the heart, the skin and with huIL-10 gene-transduced FLSC. Microchimerism was checked using fluorescent flow cytometry, huIL10 production using enzyme-linked immunosorbent assay (ELISA), and graft survival was evaluated by daily observation. Significant level of huIL10 (up to 900 pg/mL) was detected for more than 2 weeks in the serum of mice that underwent transplantation. Four weeks after the FLSC injection, microchimerism was identified in the recipient lymphoid organs (spleen, thymus, and bone marrow) by the presence of donor cells (H-2b). Finally, in the group of mice treated with huIL-10 gene-transduced FLSC, skin allografts survived for 18.9 +/- 1.8 days compared with 9.5 and 9.6 days in the groups of mice treated with nontransduced FLSC or huIL-10 alone, respectively. The same pattern for heart allograft survival was observed. HuIL-10 transduction of donor hematopoietic stem cells resulted in production of huIL-10, cell engraftment, and chimerism. Although full tolerance was not obtained, specific and highly significant (P < .001) prolongation of the survival of donor heart allografts with (more than 2-fold compared with nontreated groups) was observed. The infiltration of the transplanted heart and its late rejection demonstrate that stem cells transduced with huIL-10 gene induce "prope" tolerance in this model.

Animals↗
PubMedDate not supplied

Study of cyclooxygenase-2 in renal ischemia-reperfusion injury.

The pathogenesis of ischemia-reperfusion (I/R) injury is known to involve cytokines and particularly surface adhesion molecules, the expression of which initiates the attachment of inflammatory cells. Cyclooxygenase (COX)-1 and COX-2 catalyze the initial key enzymatic steps in the metabolism of arachidonic acid. COX-1 is constitutively expressed in most tissues, whereas COX-2 is induced in response to proinflamamatory cytokines and stress. In this study we examined the expression of COX-1 and COX-2 in the rat after 90 minutes of warm-I/R injury. Rats were sacrificed at 0, 1.5, 3, 5, 12, and 24 hours after reperfusion. COX-2 expressions were analyzed by immunohistochemical staining, which was graded on a scale of 0 to 4. All results are presented as the mean values +/- SD. Data analyses used analysis of variance. COX-2 expression was most intense on endothelial cells at 3 and 5 hours after reperfusion. From 12 to 24 hours after reperfusion COX-2 expression on endothelial cells gradually became weaker. COX-2 expression scores were significantly higher at 1.5, 3, 5, 12, and 24 hours after reperfusion than at 0 hours. However, there were no differences in COX-1 expression after reperfusion. Several hours after the maximum of COX-2 expression the maximum renal I/R injury was observed. These results suggest a relationship between COX-2 expression and renal I/R injury.

Animals↗